Chinook climates pose special challenges to gardeners

Fundamentals Of Chinook Gardening
Tips For Success In Chinook Climates
by Linda Tomlinson, Guest Writer

Gardening in the Chinook region certainly has its challenges. Temperatures can fluctuate rapidly during winter months, changing a bitterly cold day into one where water runs down the street in a matter of hours. The strong winds that blow in the Chinooks melt the snow and dry out the landscape.

Despite the somewhat milder winters, it is it next to impossible to grow broadleaf evergreens in Chinook conditions, as the plants lose too much moisture through transpiration right through the winter. On the other hand, the narrow needles and scales of juniper, cedar, spruce and pine trees usually fare better as long as they are not placed on southern or western exposures.

	Evergreens wrapped in burlap

Wrapping evergreens in a protective wrap such as burlap will shield the plants from the drying sunlight and winds. Place the protective material loosely around the plants after the ground is frozen, and remove it in the spring when the soil will absorb moisture once again. Make it look as attractive as possible, as it will be part of the landscape for at least 6 months.

Consider mulching your plants every fall, as snow cover is often nonexistent in a Chinook climate. While this lack of snow may be great for the residents of cities and towns in these regions, it leaves plants without any insulation against the cold or dramatic and sudden temperature changes which can and do occur.

Mulch secured with wire mesh

Covering perennial and shrub beds with a 15 - 20 cm (6 -8 in.) mulch will insulate the plants’ roots against fluctuations in air temperature. Fallen leaves, peat moss, compost or clean straw all make terrific mulches. When applying the mulches, be sure that there are not large air holes near the plant roots. In windy areas, place branches on top of the mulch to keep it in place over the winter. Come spring, you can incorporate some of the mulch into the soil, and the rest can be composted.

The difference between a good garden and a great one is often found in the soil. Add compost and other organic material yearly to amend the soil, replacing lost nutrients and building soil structure. Healthy soil produces healthy plants that are more likely to survive adverse conditions.

Use plants that are hardy to the area. Some would argue that the only ones that are truly hardy are native species, but this isn’t necessarily true. Choose trees and shrubs that are rated for your hardiness zone, or even one zone colder as a measure of protection. If possible, purchase woody material that has been grown in the Chinook region. This way, you can be sure that the weaker plants will have died in the growing fields, leaving only the hardy ones for market. Yes, these plants are more expensive than plants trucked in from warmer climates, but they are also more likely to survive, and that’s what’s important.

	Tender shrub protected with leaf mulch

This is not to say that all plants that are grown in warmer climates will die; many will go on to become fine specimens. But their initial growth will likely be slower while they establish themselves and adjust to their new climate. It is even possible for some plants to grow for a number of years before eventually succumbing to winterkill, much to the dismay of the homeowner.

Tender plants can be grown successfully if mulched and positioned properly. Build a cage around small tender shrubs and fill it with mulch, to insulate them from the cold. Do not remove the mulch until all danger of low temperatures has past. If removed too early, the fluctuating frost and heat cycles of spring will kill these tender plants.

Place tender plants in areas that are protected from westerly winds and southern exposures. The winds will dry out the plants causing dessication and tissue death, while the heat of the sun causes them to break dormancy prematurely, before winter and the threats of spring frosts are over.

Standing perennial stalks help trap snow in winter

Do not fertilize plants after the middle of July or the first of August. Plants need to stop putting out new growth and harden up in preparation for winter. Plants that continue to grow into the fall are soft and full of moisture. The liquid in the cells expands when it freezes, rupturing the cell walls and killing that part of the plant.

Water all plants after the first killer frost in the fall when they have gone dormant for the season, and again just before the ground freezes for the winter. Wet soil will freeze harder and stay frozen longer than a dry soil, and will make moisture available to the plants during warm spells and in early spring. Water evergreens and beds with a southern exposure when the temperature reaches plus 10°C (50°F) during Chinooks. This will help replenish moisture lost to the sun and warm winds.

With careful plant selection, good soil, mulch and extra water, gardening in Chinook country can be an enjoyable, rewarding and successful venture.

Linda Tomlinson is a freelance garden writer and substitute teacher who lives on an acreage near Rocky Mountain House, Alberta, with her husband and children. Her practical gardening column appears every Thursday in the Red Deer Advocate. A graduate from the Olds College horticultural program, she is always on the lookout for exciting yards to feature in Alberta Gardening.

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